Kevin Cook, noted book and pulp collector, provides a footnote to his recent musings:
The adventure novel King Solomon’s Mines was not H. Rider Haggard’s first book, but it introduced the protagonist Allan Quatermain. In between King Solomon’s Mines and Allan Quatermain he wrote She.
Another nugget about H. Rider Haggard that I find unique, something that he is not often given credit for starting, is that in Allan Quatermain — only the second Quatermain book — Haggard killed off the character. He would spend the rest of his career writing additional Allan Quatermain stories or novels to fill in the gaps in his life.
Skip forward several decades and Michael Moorcock, in his first book, The Stealer of Souls, introduces Elric. In the second Elric book, Stormbringer, Moorcock kills off Elric and then spends the rest of his career (still ongoing) writing Elric stories and novels to fill in the gaps in his life.
David Gemmell did them one better, killing off his most famous character, Druss the Legend, in his first book, Legend. Gemmell continued writing Druss novels for the rest of his career, filling in the gaps in his life.
Notice a trend?
They’re all British authors. Must be something in all the tea they drink over there.
Seriously, I do not believe that anyone has given Haggard credit for originating this pattern.